Battery including a fluid manager mounted external to cell

ABSTRACT

A fluid consuming battery ( 10 ) is provided with a fluid regulating system ( 50 ) for regulating fluid entry into the battery. The battery ( 10 ) includes a fluid consuming cell ( 20 ) having a cell housing with fluid entry ports for the passage of a fluid into the cell housing. A first fluid consuming electrode and a second electrode are disposed within the cell housing. The fluid regulating system ( 50 ) includes a valve having a moving plate ( 66 ) disposed adjacent to a fixed plate ( 62 ). The moving plate and fixed plate both have fluid entry ports ( 68, 64 ) that align in an open valve position and are misaligned in a closed valve position. The fluid regulating system ( 50 ) also includes an actuator that may include one or more shape memory alloy (SMA) components ( 82   a   , 82   b ) for moving the moving plate ( 66 ) relative to the fixed plate ( 62 ) to open and close the valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/790,876, filed on Apr. 11, 2006, U.S. Provisional Application No.60/817,199, filed on Jun. 28, 2006, and U.S. Provisional Application No.60/860,175, filed on Nov. 20, 2006, the entire disclosures of each ofthe above applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates to fluid regulating systems for controlling therate of entry of fluids, such as gases, into and out of electrochemicalbatteries and cells with fluid consuming electrodes, and to thebatteries and cells in which such fluid regulating systems are used,particularly air-depolarized, air-assisted and fuel cells and batteries.

Electrochemical battery cells that use a fluid, such as oxygen and othergases, from outside the cell as an active material to produce electricalenergy, such as air-depolarized, air-assisted and fuel cell batterycells, can be used to power a variety of portable electronic devices.For example, air enters into an air-depolarized or air-assisted cell,where it can be used as, or can recharge, the positive electrode activematerial. The oxygen reduction electrode promotes the reaction of theoxygen with the cell electrolyte and, ultimately, the oxidation of thenegative electrode active material with the oxygen. The material in theoxygen reduction electrode that promotes the reaction of oxygen with theelectrolyte is often referred to as a catalyst. However, some materialsused in oxygen reduction electrodes are not true catalysts because theycan be at least partially reduced, particularly during periods ofrelatively high rate of discharge.

One type of air-depolarized cell is a zinc/air cell. This type of celluses zinc as the negative electrode active material and has an aqueousalkaline (e.g., KOH) electrolyte. Manganese oxides that can be used inzinc/air cell air are capable of electrochemical reduction in concertwith oxidation of the negative electrode active material, particularlywhen the rate of diffusion of oxygen into the air electrode isinsufficient. These manganese oxides can then be reoxidized by theoxygen during periods of lower rate discharge or rest.

Air-assisted cells are hybrid cells that contain consumable positive andnegative electrode active materials as well as an oxygen reductionelectrode. The positive electrode can sustain a high discharge rate fora significant period of time, but through the oxygen reductionelectrode, oxygen can partially recharge the positive electrode duringperiods of lower or no discharge, so oxygen can be used for asubstantial portion of the total cell discharge capacity. This means theamount of positive electrode active material put into the cell can bereduced and the amount of negative electrode active material can beincreased to increase the total cell capacity. Examples of air-assistedcells are disclosed in commonly assigned U.S. Pat. Nos. 6,383,674 and5,079,106.

An advantage of air-depolarized, air-assisted, fuel cells is their highenergy density, since at least a portion of the active material of atleast one of the electrodes comes from or is regenerated by a fluid(e.g., a gas) from outside the cell.

A disadvantage of these cells is that the maximum discharge rates theyare capable of can be limited by the rate at which oxygen can enter theoxygen reduction electrode. In the past, efforts have been made toincrease the rate of oxygen entry into the oxygen reduction electrodeand/or control the rate of entry of undesirable gases, such as carbondioxide, that can cause wasteful reactions, as well as the rate of waterentry or loss (depending on the relative water vapor partial pressuresoutside and inside the cell) that can fill void space in the cellintended to accommodate the increased volume of discharge reactionproducts or dry the cell out, respectively. Examples of these approachescan be found in U.S. Pat. Nos. 6,558,828; 6,492,046; 5,795,667;5,733,676; U.S. Patent Publication No. 2002/0150814; and InternationalPatent Publication No. WO02/35641. However, changing the diffusion rateof one of these gases generally affects the others as well. Even whenefforts have been made to balance the need for a high rate of oxygendiffusion and low rates of CO₂ and water diffusion, there has been onlylimited success.

At higher discharge rates, it is more important to get sufficient oxygeninto the oxygen reduction electrode, but during periods of lowerdischarge rates and periods of time when the cell is not in use, theimportance of minimizing CO₂ and water diffusion increases. To providean increase in air flow into the cell only during periods of high ratedischarge, fans have been used to force air into cells (e.g., U.S. Pat.No. 6,500,575), but fans and controls for them can add cost andcomplexity to manufacturing, and fans, even micro fans, can take upvaluable volume within individual cells, multiple cell battery packs anddevices.

Another approach that has been proposed is to use valves to control theamount of air entering the cells (e.g., U.S. Pat. No. 6,641,947 and U.S.Patent Publication No. 2003/0186099), but external means, such as fansand/or relatively complicated electronics, can be required to operatethe valves.

Yet another approach has been to use a water impermeable membranebetween an oxygen reduction electrode and the outside environment havingflaps that can open and close as a result of a differential in airpressure, e.g., resulting from a consumption of oxygen when the batteryis discharging (e.g., U.S. Patent Publication No. 2003/0049508).However, the pressure differential may be small and can be affected bythe atmospheric conditions outside the battery.

Commonly assigned U.S. Patent Publication No. 2005/0136321 discloses avalve that is operated by an actuator that responds to changes in apotential applied across the actuator to open and close the valve.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a battery is providedthat comprises: a cell housing having at least one fluid entry port forthe passage of a fluid into the cell housing; a first fluid consumingelectrode disposed within the cell housing; a second electrode disposedwithin the cell housing; and a fluid regulating system disposed so as toselectively allow fluid to enter into the at least one fluid entry portso as to reach the first fluid consuming electrode. The fluid regulatingsystem comprises: a moving plate disposed adjacent an outer surface ofthe cell housing and having at least one plate aperture for moving inand out of alignment with the at least one fluid entry port; and anactuator comprising a shape memory alloy component for moving the movingplate when heat is applied to the shape memory alloy component.

According to another aspect of the present invention, a battery isprovided that comprises: a cell housing having at least one fluid entryport through a side of the cell housing for the passage of a fluid intothe cell housing; a first fluid consuming electrode disposed within thecell housing; a second electrode disposed within the cell housing; and afluid regulating system disposed so as to selectively allow fluid toenter into the at least one fluid entry port so as to reach the firstfluid consuming electrode. The fluid regulating system comprises: amoving plate disposed adjacent an outer surface of the cell housing andhaving at least one plate aperture for moving in and out of alignmentwith the at least one fluid entry port; and an actuator for moving themoving plate, and a lid covering the moving plate and providing apassage for fluid to the moving plate.

These and other features, advantages, and objects of the presentinvention will be further understood and appreciated by those skilled inthe art by reference to the following specification, claims, andappended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of a battery constructed in accordance witha first embodiment of the present invention showing the top of thebattery;

FIG. 2 is a perspective view of the battery shown in FIG. 1 showing thebottom of the battery;

FIG. 3 is an exploded perspective view showing the bottom of the batteryalong with the components forming a fluid regulating system used withthe battery;

FIG. 4 is a perspective view of the first construction of a fluidregulating system useful in the battery shown in FIGS. 1 and 17;

FIGS. 5A and 5B are partial cross-sectional views illustrating the valveof the fluid regulating system in open and closed positions;

FIG. 6 is a perspective view of an alternative construction of a fluidregulating system useful in the batteries of FIGS. 1 and 17;

FIG. 7 is a schematic view of a first alternative actuator constructionfor use with the present invention;

FIG. 8 is another alternative construction for an actuator useful withthe present invention;

FIG. 9 is a top view of a fluid regulating system employing anotheractuator construction and an overmolded chassis useful with the presentinvention;

FIG. 9A is a top view of a fluid regulating system employing an actuatorwith a single pin, according to another embodiment of the presentinvention;

FIG. 9B is a top view of a fluid regulating system employing analternate pin actuator assembly;

FIGS. 10A and 10B are cross-sectional views of the portion of thebattery including the valve as used in the present invention;

FIG. 11 is an alternative construction of a fluid regulating system thatmay be used in the various embodiments of the present invention;

FIG. 12 is an exploded perspective view of a variation of the battery ofthe first embodiment of the present invention;

FIG. 13 is a partial cross-sectional view of one possible implementationof the alternative battery construction shown in FIG. 12;

FIG. 14 is another possible configuration of the alternative batteryconstruction shown in FIG. 12;

FIG. 15 is a partial cross-sectional view showing a differentconstruction for the first embodiment of the present invention;

FIG. 16 is a partial cross-sectional view of yet another possibleimplementation of the first embodiment of the present invention;

FIG. 17 is an exploded perspective view of a second embodiment of abattery constructed in accordance with the present invention;

FIG. 18 is a partial cross-sectional view of the battery shown in FIG.17;

FIG. 19 is a cross-sectional view showing the details of an electricalcontact tab that may be used with either the first or second embodimentof the present invention;

FIG. 20 is a partial cross-sectional view showing an alternativeconstruction of a battery according to the second embodiment of thepresent invention;

FIG. 21 is a partial perspective view of a modified can that may be usedin the construction shown in FIG. 20;

FIG. 22 is a partial perspective view of a gasket that may be used inthe construction shown in FIG. 20;

FIG. 23 is a cross-sectional view of a portion of the gasket shown inFIG. 22;

FIG. 24 is an exploded perspective view of a gasket and cover that maybe used in a battery constructed in accordance with a third embodimentof the present invention;

FIG. 25 is a cross-sectional view of a battery constructed in accordancewith a fourth embodiment of the present invention;

FIG. 26 is a cross-sectional view of a battery constructed in accordancewith a fifth embodiment of the present invention;

FIG. 27 is a partial cross-sectional view of a portion of the batteryshown in FIG. 26, but with the valve in a closed position;

FIG. 28 is a perspective view of a valve member useful in the batteryshown in FIG. 26;

FIG. 29 is an exploded perspective view of a battery in accordance witha sixth embodiment of the invention, with the fluid regulating systemactuators and control circuit not shown;

FIG. 30 is a cross-sectional view of the fluid regulating system of thebattery shown in FIG. 29, as viewed from the right side;

FIG. 31 is a cross-sectional view of a fluid regulating system inaccordance with a seventh embodiment of the invention;

FIG. 32 is an exploded partial perspective view of a portion of a fluidregulating system in accordance with an embodiment of the invention;

FIG. 33A is a top view of an embodiment of a valve in a closed positionand including a schematic diagram of a portion of a control circuit;

FIG. 33B is a top view of an embodiment of the valve shown in FIG. 33A,but with the valve in an open position;

FIG. 33C is a top view of an embodiment of the valve shown in FIG. 33B,but with an actuator in an elongated condition;

FIG. 33D is a top view of an embodiment of the valve shown in FIG. 33A,but with both actuators in a shortened condition;

FIG. 34 is a top view of a portion of a fluid regulating system inaccordance with an embodiment of the invention;

FIG. 35 is a perspective of an SMA wire fastened to a connector;

FIG. 36 is a partial perspective view of a fluid regulating systememploying a pivoting lever having a sliding electrical contact,according to another embodiment of the present invention;

FIG. 37 is a top view of the portion of the fluid regulating systemshown in FIG. 36 illustrating rotation of the lever and sliding contact;

FIG. 38 is a partial perspective view of a fluid regulating systememploying a pivoting lever having an alternate electrical connection,according to another embodiment;

FIG. 39 is an exploded perspective view of a fluid regulating systememploying a rotational lever, according to another embodiment of thepresent invention;

FIG. 40 is a top view of the fluid regulating system of FIG. 39 shown inthe open valve position;

FIG. 41 is a top view of the fluid regulating system of FIG. 39 shown inthe closed valve position;

FIG. 42 is an exploded perspective view of a fluid regulating systememploying a lever that pivots about a flexible hinge, according toanother embodiment;

FIG. 43 is a top view of the fluid regulating system of FIG. 42 shown inthe open valve position;

FIG. 44 is a top view of the fluid regulating system of FIG. 42 shown inthe closed valve position;

FIG. 45 is a top view of a fluid regulating system employing a passiveclosure actuator, according to one embodiment;

FIG. 46 is a perspective view of a battery having a fluid regulatingsystem with a pressure release fluid path provided in the chassis,according to another embodiment;

FIG. 47 is an exploded perspective view of the battery having a fluidregulating system with a pressure release path shown in FIG. 46;

FIG. 48 is a cross-sectional view of a portion of the battery and fluidregulating system taken through lines XLVIII-XLVIII of FIG. 46;

FIG. 49 is a cross-sectional view of the chassis taken through linesXLIX-XLIX of FIG. 47 further illustrating baffles forming a tortuousfluid passage;

FIG. 50 is an exploded perspective view of a battery having a fluidregulating system with a pressure relief fluid path, according toanother embodiment;

FIG. 51 is a perspective view of a fluid regulating system employing arotational moving plate shown in a closed valve position, according toanother embodiment;

FIG. 52 is a perspective view of the fluid regulating system of FIG. 51shown in the open valve position;

FIG. 53 is a top view of a fluid regulating system employing arotational moving plate in the open valve position, according to afurther embodiment; and

FIG. 54 is a top view of the fluid regulating system of FIG. 53 shown inthe closed valve position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of this invention include a battery that includes anelectrochemical cell that utilizes a fluid (such as oxygen or anothergas) from outside the cell as an active material for one of theelectrodes. The cell has a fluid consuming electrode, such as an oxygenreduction electrode. The cell can be an air-depolarized cell, anair-assisted cell, or a fuel cell. The battery also has a fluidregulating system for adjusting the rate of passage of fluid to thefluid consuming electrode (e.g., the air electrodes in air-depolarizedand air-assisted cells) to provide a sufficient amount of the fluid fromoutside the cell for discharge of the cell at high rate or high power,while minimizing entry of fluids into the fluid consuming electrode andwater gain or loss into or from the cell during periods of low rate orno discharge.

Preferably the fluid regulating system will have a fast response tochanges in cell potential, a long cycle lifetime, a low operatingvoltage that is well matched to the cell voltage range on discharge, anda high efficiency. In addition, the regulating system will preferablyhave a low permeability to the fluids being managed in the closedposition, open and close in proportion to the need for the active fluidin the cell, require only a very small amount of the total celldischarge capacity, have a small volume and be easy and inexpensive tomanufacture and incorporate into or onto the cell.

As used herein, unless otherwise indicated, the term “fluid” refers tofluid that can be consumed by the fluid consuming electrode of a fluidconsuming cell in the production of electrical energy by the cell. Thepresent invention is exemplified below by air-depolarized cells withoxygen reduction electrodes, but the invention can more generally beused in fluid consuming cells having other types of fluid consumingelectrodes, such as fuel cells. Fuel cells can use a variety of gasesfrom outside the cell housing as the active material of one or both ofthe cell electrodes.

As described further below with respect to FIGS. 1-3, a battery 10constructed in accordance with the present invention includes a fluidconsuming cell 20 and a fluid regulating system 50. The fluid regulatingsystem 50 regulates the flow of fluid to the fluid consumingelectrode(s) of fluid consuming cell 20. For an air-depolarized cell,the fluid regulating system is disposed on the inside or outside of acell housing 30 of fluid consuming cell 20 and on the air side of theoxygen reduction electrode (i.e., on, or a part of, the surface of theoxygen reduction electrode that is accessible to air from the outside ofthe cell housing).

A first embodiment of a battery 10 constructed in accordance with thepresent invention is shown in FIGS. 1-3. As shown, fluid consuming cell20 (in this case an air-depolarized cell) includes a cell housing 30,which includes a first housing component and a second housing component,which may include a can 34 and a cover 36, respectively, or may haveshapes or sizes differing from what would otherwise be considered a canor cover. For purposes of example, the first housing component ishereinafter referred to as can 34, while the second housing component ishereinafter referred to as cover 36. Can 34 and cover 36 are both madeof an electrically conductive material, but are electrically insulatedfrom one another by means of a gasket 38 (FIG. 13). Can 34 generallyserves as the external positive contact terminal for the fluid consumingcell 20, whereas cover 36 serves as the external negative contactterminal. As discussed further below, cell 20 further includes a firstelectrode 40, which may be the fluid consuming electrode or airelectrode, a second electrode 42, which may be the negative electrode(i.e., anode), and a separator 44 disposed between the first and secondelectrodes (see FIG. 13). First electrode 40 is preferably electricallycoupled to can 34, whereas second electrode 42 is preferablyelectrically coupled to cover 36.

Can 34 includes a bottom surface 35 in which a plurality of fluid entryports 32 are provided such that fluid may pass to the interior of cellhousing 30 so as to reach the fluid consuming electrode 40 (see FIG.13).

In the embodiment shown in FIGS. 1-3, a fluid regulating system 50 issecured to the exterior of bottom surface 35 of can 34. The particularmanner by which fluid regulating system 50 may be attached to theexterior of cell 20 is discussed further below. In addition, furtherembodiments are described below in which fluid regulating system 50 isincorporated on the inside of fluid consuming cell 20.

The fluid regulating system 50 according to this particular embodimentmay include a valve 60 including a first plate 62 (which may correspondto bottom surface 35 of can 34) having a plurality of apertures 64(which may correspond to fluid entry ports 32), and a movable secondplate 66 including a plurality of apertures 68 that correspond in size,shape, number, and position to apertures 64 formed in first plate 62.The size, shape, number, and position of apertures 64 and 68 arepreferably optimized to provide the desired volume and distribution offluid applied to the fluid consuming electrode. The size, shape, numberand relative location of apertures, 64 do not have to be the same as thesize, shape, number and relative location of apertures 68. For example,if apertures 64 are slightly different in size from apertures 68,precise alignment of apertures 64 and 68 is not essential to achieve themaximum total open area through plates 62 and 66.

Fluid regulating system 50 may further include a chassis 70 having anannular body portion 72 with an opening 74 in which second plate 66 isdisposed. Opening 74 is preferably shaped and sized to contact theelongated side edges of plate 66 while providing excess space at theshorter side of plate 66 such that plate 66 may be slid linearly alongan axis in parallel with its longest dimension. Thus, as shown in FIGS.5A and 5B, the apertures 68 of second plate 66 may be moved into and outof alignment with apertures 64 of first plate 62 to thereby open andclose valve 60. The chassis is preferably configured as furtherdiscussed below, to guide and possibly retain second plate 66 adjacentthe first plate 62. As shown in FIGS. 5A and 5B, a lubricating layer 69made of oil or TEFLON® may be disposed between plates 62 and 66 toenable second plate 66 to more readily slide along the surface of plate62. Thus, lubricating layer 69 enables the valve to be opened and closedrequiring less force by the actuator. In addition, because it may bedifficult to get the surfaces of plates 62 and 66 to be sufficientlysmooth so as to provide a good seal, the lubricating fluid 69 may beutilized to enhance the sealing characteristic of the valve withoutrequiring complex and expensive machinery of the plates to otherwisefurther smooth their surfaces. Second plate 66 may be made of a magneticmaterial, such as that commonly used in the gaskets provided onrefrigerators. By utilizing a magnetic plate 66, chassis 70 does notneed to be configured so as to include any mechanism for otherwiseholding plate 66 firmly against plate 62. The magnetic plate 66 ispreferably a flexible, magnet that can conform to the shape of adjacentplate 62. Magnetic plate 66 can be made from suitable magnetic material,such as a blend of ferromagnetic (e.g., barium/strontium ferrite) andelastomeric materials. The magnetic plate 66 can be a permanent magnetthat does not consume energy from the cell 20 to maintain sufficientmagnetic force. In the embodiments shown in FIGS. 3 and 12, moveablesecond plate 66 can be constrained on the top and bottom by a lid 100(as described further below) and bottom surface 35 of can 34. In analternative embodiment, battery 10′ has a fluid regulating system 50′shown in FIGS. 29 and 30. The chassis 70′ is taller than chassis 70 inFIGS. 3 and 12. This can facilitate the movement of fluid between thelid 100 and the moveable plate 66, thereby providing more uniformdistribution of fluid across the surface of plate 66 and more uniformflow of fluid through apertures 68 and 64 when plates 66 and 62 arealigned in an open position.

Chassis 70′ can include an inward extending ledge 71, creating a race orgroove 73 within which plate 66 can slide. The vertical position ofledge 71 can be selected to create a race 73 of the desired dimensionsto hold plate 66 firmly enough against surface 35 to provide a good sealwhen plates 66 and 62 are aligned in a closed position but not sotightly as to interfere with the desired sliding motion of plate 66.Ledge 71 can be an integral part of chassis 70′, or it can be a separatecomponent. For example, ledge 71 can be in the form of a flat washer orstrip insert molded into the chassis body 72′, or it can be a separatecomponent affixed to the chassis body 72′. The ledge 71 can be made ofthe same material as chassis body 72′ or a different material. Materialsfor the chassis body 72′ and ledge 71 can be selected to provide boththe desired strength and smooth sliding of plate 66 within the race 73.If either the chassis body 72′ or ledge 71 is made from an electricallyconductive material, insulation from the electrical components of theactuator 80 and control circuit 90 may be required. As an alternative toa continuous ledge, a series of projections can be used.

The ledge 71 and/or chassis body 72′ can also be modified to incorporateone or more additional structures, such as ribs extending across theopening 74′ above plate 66, to hold the central portion of plate 66flat. Alternatively, downward projections from the lid 100 can be usedto hold the central portion of plate 66 flat.

The chassis 70′ can include a second race 77 in which the lid 100 isheld, as shown in FIG. 31. This second race can be formed by one or moreadditional ledges 79 a and 79 b. This arrangement can facilitatepre-assembly of the lid and components of the fluid regulating system,to be added to the fluid consuming cell at another step in themanufacturing process. In another embodiment in which the stationaryplate 62 is not a surface 35 of the can 34, the chassis 70′ can includeanother ledge (not shown) below ledge 71, forming a larger race thatretains the stationary plate 62 as well as movable plate 66.

The ledge 71 of chassis 70′ can be a continuous ledge extending aroundthe entire perimeter of opening 74′, or it can be a discontinuous ledgeextending along only part of the perimeter, as shown in FIG. 29. If thediscontinuous ledge is suitably located and the moving plate 66 issufficiently flexible, if the pressure within the cell becomesexcessive, the edge of the moving plate 66 can bow outward between theends of the discontinuous ledge 71 to provide a passageway between theplate 66 and both plate 62 and chassis frame 72′ through which gases canescape to the external environment when the valve is partially open orclosed. In such embodiments the plate 66 preferably has spring-likeproperties so that when the internal cell pressure is sufficientlyreduced the plate 66 will again conform to the shape of the surface 35of the can 34.

In an alternative embodiment in which the lid serves as the stationaryvalve plate and the moveable plate is disposed adjacent to the lid, thechassis can include a ledge to hold the moveable plate against the lidwhile maintaining a space between the moveable plate and the surface ofthe can bottom, to facilitate uniform air distribution to the aperturesin the can. As described above, this embodiment can also include asecond race in the chassis in which the lid is held.

The fluid regulating system can be actuated in response to the voltageof the fluid depolarized cell, as described below, or it can be actuatedby the user, or a combination of methods can be used. For example, whenthe user of a device powered by the device turns the device switch tothe on position, the valve can be initially opened by mechanical action,and when the user turns the device switch to the off position, the valvecan be initially closed by mechanical action. While the device switchremains in the on position, a control circuit can control the operationof the valve. In another example, when the device is turned on, powerfrom the cell can be applied to the fluid regulating system to initiallyopen the valve, and when the device is turned off, the valve can beactuated to close.

An actuator is preferably provided as a part of fluid regulating system50 to actuate valve 60. The actuator may include a control circuit 90that senses the voltage of fluid consuming cell 20 and which generates acontrol signal in response to the detected cell voltage. Circuit 90 maybe an application specific integrated circuit (ASIC), which ispreferably mounted on a surface of chassis 70. The body 72 of chassis 70is preferably made of a non-conductive material such that tracings 96and 98 may be printed on a surface of the chassis as further discussedbelow. Chassis 70 may thus be a printed circuit board. The chassis couldbe molded or shaped and most or all of the electrical connections couldbe pressure contacts to minimize the sophistication of assembly. Thechassis may, however, require some machining and some electricalconnections and may require some soldering or welding. The selection ofthe chassis material may be based on its compatibility with itsmulti-functional use as a frame to house the valve, as a printed circuitboard for the electronics, and for its ability/compatibility to beattached to the cell. A strategic depression may be provided in and/oron a laminar structure of the chassis for mounting the control circuit90. This would allow any mounted parts to be maintained flush with thesurface of the chassis to facilitate assembly with the cell. It is alsopossible that it may become desirable to coat the printed circuittracings such as tracings 96 and 98 with a nonconductive material toprevent shorting if pressed against a metal lid 100 or can 34.Alternatively, one or more recesses may be provided in the chassis, suchas by molding or machining, to accommodate all or a portion of one ormore components of the control circuit and the actuator. These recessescan be useful to allow positioning of components in different locationson the chassis and anchoring of components that extend beyond thechassis frame, as described below.

As a platform for the electronics, it would be desirable for the basematerial of chassis 70 to be an existing PCB material. The most commonbase materials contain epoxy resins and fiberglass reinforcement. It maybe desirable for chassis 70 to be of laminar construction to integrateand protect the electronic circuit components, as well as to maintain aflush surface, parallel with bottom surface 35 of can 34. As describedabove, the inside diameter of the chassis may utilize a metal race fordurability to house sliding valve plate 66. The race may “lock” plate 66in place (so it does not fall out), provide enough axial force toprevent the valve from separating during use but insufficient force toprevent plate 66 from sliding. The chassis may thus be formed, molded,or machined, dependent on the material selection, so as to achieve thevalve race shape, whether metal or not, to flush mount a chip and togenerate vias (through-holes). There may be conductive circuitry withinthe vias, on one side and an edge of a chassis if mounted external tothe cell, or on both sides of chassis 70 if mounted internal to thecell.

A conductive pathway for circuit 90 may be provided on both sides ofchassis 70 and within the vias. This may be accomplished by a platingprocess or screen printing a conductive paste, especially to fill thevias. Conductive foil could be applied to the substrate at formation andthe unwanted portion etched away. Copper is the most common materialused. It may require multiple layers and multiple materials to assureadherence to the substrate depending on the base material utilized.

One method of attaching an ASIC serving as control circuit 90 is to usea direct method, as opposed to a packaged chip, due to volumeconstraints. Common methods of direct chip attachment include wirebonding and flip chip. Wire bonding would use wires about 0.02 mm(0.0008 inch) in diameter that are bonded to the four to six chip padsand the circuit substrate. The chip and wire bonds may be encapsulatedin non-conductive epoxy for protection. With a flip chip attachment, thepads may be pre-finished with a Pb/Sn solder and, in turn, soldered tothe substrate. Once attached, the chip may be encapsulated withnon-conductive epoxy to provide protection.

In the embodiment shown in FIGS. 3 and 4, the actuator further includesa plurality of shape memory alloy (SMA) components that particularlyinclude a first SMA wire 82 a and second SMA wire 82 b. The SMA wiresare secured at either end of the chassis 70 and are electrically coupledto tracings 96 and 98, which extend from control circuit 90 to anopposite side of chassis 70. By supplying a control signal that passes acurrent through SMA wires 82 a and 82 b, the control circuit 90 maycause the SMA wires to heat up, which causes the SMA wires to expand orconstrict to a particular length. This in turn causes the SMA wires 82 aand 82 b to pull second plate 66 in one direction or opposite directionand thus causes plate 66 to slide in and out of an open or closedposition so as to selectively allow fluid (i.e., air) to pass into theinterior of cell housing 30.

As shown in FIG. 4, two contact terminals 92 and 94 are provided onchassis 70 for connection to the positive and negative terminals of cell20. The contact terminals 92 and 94 may be provided on any surface ofchassis 70, and as discussed below, it may be preferable to provide oneof the contact terminals, particularly terminal 94, on an outer facingedge surface of chassis 70 such that it may be exposed to the outside ofthe battery assembly for subsequent connection to the cover 36 of cell20. Contact terminal 92, on the other hand, may best be provided on aninner surface that is either pressed into electrical contact with aconductive portion of lid 100 or on the opposite surface in electricalconnection with the bottom surface 35 of can 34. The manner by whichelectrical connections of contact terminals 92 and 94 are made to can 34and cover 36 of cell 20 are discussed further below.

As shown in FIG. 3, fluid regulating system 50 may further include a lidor cover 100 that extends over and optionally around chassis 70 toprotect and shield fluid regulating system 50. Lid 100 preferablyincludes one or more holes 102 to allow fluid to pass from the outsideto valve 60 for selective passage into cell 20. As mentioned above, lid100 may serve as first plate 62.

Preferably valve 60 is in an open condition when a current is appliedindicating that cell 20 is in use, and is closed when a current is notapplied indicating that the cell is not in use. In the embodimentsdiscussed with respect to FIGS. 3, 4, 6, 7, 8, 12, 32, 33A-D, 34, 36-44,53, and 54 the SMA wires 82 a-82 e pull, but do not push the secondvalve plate 66. Thus, in FIGS. 3 and 4 first SMA wire 82 a pulls thevalve open, whereas second SMA wire 82 b pulls the valve closed. In theembodiment shown in FIG. 6, two wires 82 a and 82 b are utilized to pullvalve plate 66 in one direction, while two additional wires 82 c and 82d are used pull the plate in the opposite direction. In FIG. 7, twowires 82 a and 82 b are used to pull the plate 66 in one direction,while a single wire 82 c is used to pull the plate 66 in the oppositedirection. In FIG. 8, three wires 82 a, 82 b, and 82 c are used to pullthe plate in one direction while two wires 82 d and 82 e are used topull the plate in the opposite direction. The SMA wires 82 may bedisposed in parallel and are provided in a symmetric fashion about acenter point of the valve plate 66 so as to supply an even force toprevent plate 66 from binding within chassis 70. In general, when thecurrent applied to the SMA wires is provided from the cell it can beadvantageous for current to be applied only to initiate movement of theactuator and not while the actuator is in a static condition in order toprevent unnecessary use of cell capacity. As shown, the SMA wires may bemounted to extend substantially parallel to one another. The SMA wiresmay also be mounted to extend parallel to the direction in which plate66 moves (see e.g., FIG. 3) or perpendicular to the direction in whichplate 66 moves (see e.g., FIGS. 9, 9A and 9B).

SMA wires may be made with any conventional shape metal alloy. A shapememory alloy is an alloy that can be deformed at one temperature butwhen heated or cooled returns to its previous shape. This propertyresults from a solid phase transformation, between the Martensite andAustenite phases. Preferred shape memory alloys have a two-way shapememory; i.e., the transformation is reversible, upon both heating andcooling. Examples of shape memory alloys include nickel-titanium,nickel-titanium-copper, copper-zinc-aluminum and copper-aluminum-nickelalloys, with nickel-titanium and nickel-titanium-copper being preferred.The use of nickel-titanium-copper (e.g., with about 5-10 weight percentcopper) can be advantageous for actuators that may be operated manytimes because of its resistance to fatigue. Manufacturers ofnickel-titanium and other shape memory alloys include Specialty Metals,Shaped Memory Alloy Division (New Hartford, N.Y., USA), MemryCorporation (Bethel, Conn., USA), and Dynalloy, Inc. (Mesa, Calif.,USA).

FIG. 9 shows another manner to attach to SMA wires 82 a and 82 b inorder to move plate 66. According to this variation, SMA wires 82 a and82 b are not provided to extend along the longest dimension of the plate66, they instead are substantially perpendicular to the direction ofmovement of plate 66. The first wire 82 a may be heated to cause firstwire 82 a to contract, while second wire 82 b is not heated allowingthat wire to flex. Thus, the plate 66 may be shifted in a firstdirection (to the right in FIG. 9 as shown with solid lines). To movethe plate in the opposite direction (i.e., to the left), a current maybe removed from wire 82 a thus allowing wire 82 a to cool and flex,while a current may be applied to wire 82 b thus heating wire 82 b andcausing it to contract. This causes the plate and wires to move to theposition shown in dashed lines in FIG. 9.

The chassis 70 is shown having control circuit 90 and circuit tracesformed on the top surface of the chassis body 72. Additionally, the SMAwires 82 a and 82 b are attached to a top surface of the chassis 70 inelectrical contact with the circuit traces. The chassis 70 is furthershown in FIG. 9 having an overmold body 300 formed over the controlcircuit 90 and circuit traces so as to encapsulate and protect thecomponents provided on chassis 70. Thus, the overmold body 300 serves aspart of the chassis 70. The overmold body 300 may include anon-conductive epoxy or other overmolding material. Additionally, theovermold body 300 is further shown including integrally formed ribs 302which extend across the opening 74 above moving plate 66. The ribs 302are shown formed in a generally V-shape and serve to hold the centralportion of the moving plate 66 flat above the underlaying fixed plate62. In one embodiment, the fixed plate 62 is connected to the bottomside of chassis 70 or its overmold body 300 and the battery cell isconnected to the top side of the overmold body 300 of chassis 70.

In the embodiment shown in FIG. 9, the first and second SMA wires 82 aand 82 b engage separate actuator pins 304 a and 304 b, respectively,which are connected to the moving plate 66. In the embodiment shown inFIG. 9A, a single actuator pin 304 may be utilized in the fluidregulating system 50. With a single actuator pin 304, the first SMA wire82 a engages one side of pin 304, while the second SMA wire 82 b engagesthe opposite side of pin 304, such that SMA wires 82 a and 82 b actuatepin 304 in opposite directions to move plate 66 left and right to openand close the valve. In this embodiment, the actuator pin 304 mayinclude wire receiving portions, such as detents or slots, at differentelevations to engage the corresponding SMA wires 82 a and 82 b atdifferent heights, such that the SMA wires 82 a and 82 b do not contactor otherwise interfere with each other.

Referring to FIG. 9B, an alternate actuator pin 304 is shown employed ina fluid regulating system 50, according to another embodiment. Pin 304is shown including first and second portions 306 a and 306 b that areelevated above the remainder of the generally rectangular pin 304 suchthat the SMA wire 82 a engages portion 306 a and SMA wire 82 b engagesportion 306 b. Portions 306 a and 306 b may include upstanding membersas shown. Alternately, portions 306 a and 306 b may include slots formedwithin a pin or other structure 304. Accordingly, single or multipleactuator engagement structures may be employed to allow the SMA wires 82a and 82 b to actuate the moving plate 66 in either direction to openand close the valve.

FIGS. 10A and 10B show two side views of valve 60 used adjacent an outersurface of can 34. FIG. 10A shows a cell at rest in which case valve 60is closed so that the apertures 64 and 68 do not align. FIG. 10B showsthe position of the valve's second plate 66 when moved into an openposition which would occur when the cell is in use. This causesapertures 64 and 68 to align and thereby allows fluid to pass into theinterior of the cell. As illustrated, SMA wires 82 a and 82 b may beattached to chassis 70 by means of a pair of spring contacts 76 to whichthe SMA wires may be crimped, clamped, soldered or welded.

FIG. 11 shows another embodiment of valve 60 that may be utilized invarious embodiments of the present invention. Valve 60 includes firstplate 62 including a plurality of apertures 64. Plate 62 may be aseparate plate that is held stationary relative to chassis 70 or may bea portion of the can or cover of a cell housing 30. Plate 62 may be madeof metal, which may be magnetic or non-magnetic. Valve 60 furtherincludes second plate 66 including a plurality of apertures 68 thatcorrespond in number, size, shape, and position to apertures 64 andfirst plate 62. Plate 66 may be a magnetic or non-magnetic metal.Similar to the embodiments discussed above, a chassis 70, whichpreferably is made of an electrically non-conductive material, includesan annular body 72 with a central opening 74 for receiving plate 66.Opening 74 is configured to be slightly larger than plate 66 in onedirection so as to enable plate 66 to slide linearly relative to plate62 such that apertures 64 and 68 may be moved into and out of alignmentto open and close valve 60. The implementation shown in FIG. 11 differsfrom the implementations discussed above insofar as a lever arm 84 isutilized as a part of actuator 80. Lever arm 84 includes a pivot pin 86that is received in an aperture or a slot or recess 78 formed in chassis70 such that lever arm 84 may be pivotably secured to chassis 70. Thismay be done, for example, by enlarging and reshaping the recess 78 tofit around pivot pin 86 and partially extend into the necked areabetween the pivot pin 86 and the body of lever arm 84 in such a way asto capture pivot pin 86 within the recess 78 but still allow the leverarm 84 to pivot within the recess 78. Other means of securing the pivotpin 86 to the chassis may be used, such as a downward projection frompivot pin 86 that is received in a hole in a ledge at the bottom of therecess 78. An actuator pin 88 preferably extends downward from the bodyof lever arm 84 such that it may be received in a hole 67 formed insecond plate 66. This allows lever arm 84 to engage plate 66 and thus toslide second plate 66 relative to first plate 62. In this particularconfiguration, a pair of SMA wires 82 a and 82 b is attached via anattachment point 89 to a top surface of lever arm 84. The other ends ofwires 82 a and 82 b may be attached to chassis 70. Wires 82 a and 82 bcan be secured to recesses in the chassis, similar to recess 78, forexample. They can be secured in any suitable manner, such as withadhesives, with pins or by fitting enlarged heads into recesses withrestricted openings. The SMA wires are electrically coupled to a controlcircuit (not shown in FIG. 11) that selectively applies a current to SMAwires 82 a and 82 b in response to a sensed cell voltage. In thismanner, SMA wires 82 a and 82 b may pull the lever arm in either of twoopposing directions thus causing lever arm 84 to slide second plate 66relative to first plate 62. In this case, chassis 70 serves as amounting location for the pivot point of lever arm 84 and of the ends ofSMA wires 82 while also providing a guide for guiding plate 66 relativeto plate 62.

Other arrangements of SMA wires and levers can be used to operate avalve in a fluid regulating system. For example, SMA wires 82 a and 82 bcan be attached to lever arm 84 via two separate attachment pointsrather than a single attachment point 89. In an alternative embodiment,SMA wires 82 a and 82 b are each fastened at both ends to the chassis70, with the center of each wire connected to the lever 84 by fittingthe wires 82 a and 82 b into recessed grooves 85 in the lever arm 84, asshown in FIG. 34.

SMA wires can be connected to components of a fluid regulating system inany suitable manner. In one embodiment one or both ends of an SMA wire82 are captured within a suitably sized connector 87, as shown in FIG.35. Preferably the SMA wire 82 is crimped into the connector 87.Optionally the wire can be glued, welded or soldered to the connectorbefore or after crimping. The connector can then be inserted into acorresponding aperture in the component (e.g., chassis 70 or lever arm84) to connect the SMA wire 82 to that component. Preferably theconnector 85 is electrically conductive and can make electrical contactbetween the SMA wire 82 and a portion of the control circuit disposed onthe surface of the component defining the aperture. The connector 87 canbe held in place within the aperture by an interference fit, anelectrically conductive adhesive, solder or a weld, for example.

In embodiments in which a control circuit is used to restrict the flowof current through the SMA wire(s) to only the time required to move thevalve to an open or closed position, the SMA wires can return to theiroriginal length (e.g., elongate) after the current flow is stopped. Whenthis happens, the SMA wires may not hold the plate in the desiredposition, allowing it to slide to a partially open or partially closedposition, for example. This is particularly true when there is anopposing SMA wire for moving the sliding plate to another position;elastic tension from the unactuated opposing SMA can pull the slidingvalve as the actuated SMA elongates following the cessation of current.In such situations, the sliding plate can be held in the desiredposition until the plate is intentionally moved from that position. Anexample of a means of retaining the sliding plate in a desired positionis a latching mechanism. Any suitable mechanism can be used. In oneembodiment a spring biased detent can cooperate with a projection fromor a recess in a surface of the sliding plate. The spring force can beselected to be sufficient to keep the plate from sliding unintentionallybut weak enough to be easily overcome by the action of an opposing SMAwire to slide the plate into another desired position.

In another embodiment the sliding plate is kept from slidingunintentionally by friction between the sliding plate and another cellor fluid regulating system component. The friction between the plate andthe other component is sufficient to prevent unintentional sliding butnot so great as to interfere with the efficient movement to anotherposition by action of an opposing SMA. The friction can be controlledthrough the selection of materials for the sliding plate and the othercomponent, a coating applied to one or both parts, or the texturing ofone or both of the adjacent surfaces.

The fluid regulating system 50 may be secured to the exterior of cell 20using a variety of techniques that are discussed below. As shown in FIG.12, lid 100 may be configured to have a plurality of stand-offs 104 thatextend downward from an inner surface of lid 100 and then pass throughholes 75 in corresponding locations on chassis 70 such that thestand-offs 104 may be attached to bottom 35 of can 34. FIGS. 13 and 14show two different constructions for the configuration shown in FIG. 12.

In FIG. 13, a configuration is shown whereby the lid 100 is formed ofplastic. In this case, the stand-offs 104 may be ultrasonically weldedto the bottom surface of can 34. In this case, there would be noelectrical connection between the lid 100 and can 34.

In FIG. 14, the stand-offs 104 are provided as an indentation/protrusion106 in a metal lid 100 which may be formed by stamping or the like. Inthis case, the metal lid 100 may be resistance- or laser-welded to thebottom surface 35 of can 34.

FIG. 15 shows an alternative method of connecting chassis 70 and lid 100to the exterior of cell 20. In this case, vias 105 are provided throughthe holes 75 of chassis 70 which serve to weld lid 100 to can 34. Thisweld also provides an electrical connection between lid 100 and cell 20.

FIG. 16 shows yet another technique whereby a metal lid 100 is securedto can 34 using a conductive epoxy 107 that is provided in the holes 75of chassis 70. As yet another alternative, the fluid regulating system50 may be secured to the bottom surface of can 34 using an adhesive, acombination of an adhesive and a label (not shown), by means of a pressfit of the chassis into one or more grooves coined in the bottom surfaceof can 34, by such a press fit of the chassis in addition to utilizingan adhesive, by crimping can 34 within a second can where the secondoutermost can replaces lid 100, by soldering or welding a laminarchassis, or encapsulating the fluid regulating system 50 in an epoxy.

Although the use of SMA wires has been described above as being apreferred component of actuator 80, other components or materials mayalso be utilized, such as linear electrode-active polymers and bendingelectro-active polymers, which are associated with artificial muscles.Such materials offer potential advantages including a simpler design, noor simplified electronics, and a proportional response to voltage.

Another consideration relates to the initial activation of the battery.The battery may be built with the valve in the open position and withholes 102 protected by a tab similar to conventional button air cells.Air-up after removal of the tab would activate the cell, initiateelectronic control of the valve, and maximize the shelf life of thebattery. Alternatively, the battery could be built with a functioningfluid regulating system. This would allow the battery to be immediatelyuseable by the consumer but may also require suitable packaging andstorage conditions in the warehouse, store shelves, etc. to preventmoisture ingress in humid environments and moisture egress in dryenvironments.

In the construction discussed above, the can 34 is proposed to act asthe stationary plate 62 of valve 60. However, it may be desirable toprovide a separate fixed plate 62 rather than utilizing can 34 such thatthe can bottom will maintain its hole pattern, but may act more like anair diffuser rather than an integral part of the valve assembly. Inaddition, the stationary plate 62 may be spaced apart from the canbottom such that if the can 34 bulges, bows, or possibly wrinkles, itwill not disrupt the operation of the valve 60. It should be noted thatthe can 34 may be made with a stronger material, a greater thickness, ora different shape (e.g., ridges in the bottom). An additional advantageof utilizing a separate stationary plate 62 is that the valve 60 may betotally preassembled thus providing a greater stability of thelubricating fluid layer 69. This may come, however, at the cost of athicker battery.

Although not illustrated in the drawing figures, a label may be providedto the outer surface of cell housing 30. Such a label may extend aroundthe perimeter of the cell so as to further cover the electricalconductor tab 110 (discussed below) as well as the interfaces betweenthe fluid regulating system 50 and cell 20 and to cover the interfacebetween the can 34 and cover 36. Sufficient portions of the cover 36 andthe can 34 and/or a conductive lid 100 could remain exposed to provideelectrical contact terminals on the outside of the battery.

The particular cell construction illustrated in FIGS. 1-3 is a novelprismatic cell design. The construction differs from a conventionalbutton-type air cell in the relative size and rectangular nature of thiscell. Similar air electrodes, anodes, separators and can/cover materialsmay thus be utilized in cell 20 that are presently used in conventionalair cells. It should be appreciated by those skilled in the art,however, that the cell 20 need not have the particular shape, size, orrelative dimensions as that shown in the drawings.

FIG. 17 shows an alternative embodiment of the present invention wherebythe fluid regulating system 50 is disposed in the interior of cellhousing 30. FIG. 18 shows a cross-sectional view of a portion of thisembodiment. As shown in these figures, the cell housing is constructedin a similar manner to that described above with the exception that thecell may be slightly thicker to accommodate the fluid regulating system50 between air electrode 40 and the inner surface of can 34. In thisembodiment, a chassis 70 may also be utilized along with a valve,actuator, and control circuit 90 as described above when applied to theexterior of the cell. Similarly, the bottom of can 34 may serve as firstplate 62 of valve 60 and may include a plurality of fluid entry ports 32which serve as apertures 64. This embodiment differs in that respectinsofar as the second plate 66 slides along the inner surface of can 34rather than the exterior surface. In this and other embodimentsdiscussed below, the chassis 70 and hence the valve 60 may be held inplace by gasket 38.

One other difference in the construction of the cell 20 when an internalfluid regulating system 50 is utilized is that the cell should bereconfigured to allow electrical connection of both the negative andpositive contact terminals of the cell to the control circuit 90 of theactuator. One manner of making this electrical connection is shown inFIGS. 17-19. As shown in FIG. 17, a contact opening 39 is formed in thebottom surface 35 of can 34. As shown in FIG. 18, the negative contactterminal 94 is provided at a bottom of chassis 70 through a via in thechassis so as to be exposed through opening 39. In this manner, anelectrical conductor 110 may be electrically connected to cover 36 ofcell housing 30 and extend around the outside of cell 20 to the opening39 while making electrical contact with contact terminal 94. Thisprovides a connection to the negative terminal of the cell. As alsoshown in FIG. 18, the positive contact terminal 92 provided on chassis70 may be positioned so as to contact an inner surface of can 34 so asto provide a connection to the positive terminal of the cell. Asdiscussed above, contact terminals 92 and 94 may be electricallyconnected to a control circuit 90 for controlling the actuator to openand close the valve in response to a detected cell voltage or currentdraw.

As shown in FIG. 19, electrical conductor 110 may be a tab that includesa foil strip 112 that is disposed between two insulative layers, whichprevent a short circuiting of the cell between can 34 and cover 36. Afirst insulative layer 114 may be disposed between the cell housing 30and conductive foil 112. This insulative layer 114 may be made ofdouble-sided tape. The second and outer insulative layer 116 may bedisposed over the foil and may comprise a strip of single-sided tape.Although this particular external electrical connection is shown withrespect to an internal fluid regulating system 50, the same electricalconductor 110 may be applied to provide an electrical path between cover36 and a similar contact terminal 94 of the external fluid regulatingsystem shown in FIGS. 1-3. In this case, an aperture similar to contactopening 39 could be formed in lid 100 or alternatively the electricalconductor 110 may simply extend between the interface between chassis 70and can 34 or the interface between chassis 70 and lid 100.

FIGS. 20-23 show yet another manner by which electrical connection maybe made between cover 36 and terminal 94 on chassis 70. In thisembodiment, a portion of the inner surface of can 34 is coated withthree layers of materials as best shown in FIG. 21. The first layer isan electrical insulator layer 151, the second layer is an electricallyconductive layer 153 that is applied over insulator layer 151 such thatthere is no electrical connection between can 34 and conductive layer153, and the third layer is an electrically insulating layer 154 appliedover a portion of conductive layer 153 to insulate the edge of the airelectrode 40 from the conductive layer 153. As shown in FIG. 21, layers151 and 153 extend around the inner bottom corner(s) of can 34 andextend over just enough of the bottom of can 34 so as to physicallycontact terminal 94 formed on the opposing surface of chassis 70. Asmentioned above, chassis 70 may be pressed against the inner bottomsurface of can 34 by gasket 38 so that the contact between conductivelayer 153 and contact 94 is by way of such pressure. Layers 151 and 153extend up a sidewall of can 34 between an interface of can 34 and gasket38. As best shown in FIGS. 20, 22, and 23, gasket 38 may include anaperture 155 through which a rivet or pin 157 may extend. Rivet or pin157 forms an electrical connection between cover 36 and conductive layer153 through gasket 38, thereby completing the conductive path betweencover 36 and contact 94 on chassis 70. Rivet/pin 157 may be molded inplace in gasket 38. Further, more than one such rivet/pin 157 may beused. The rivet/pin 157 may have a length sufficient to allow for gasketcompression. Layers 151, 153 and 154 are in the form of a strip as shownin FIG. 21 in order to allow the edge of the air electrode 40 to makeelectrical contact with the inside surface of the can 34.

FIG. 24 shows yet another embodiment of the present invention whereby anelectrically conductive pin 157 is passed vertically downward through anaperture 155 in a flange portion 160 of gasket 38. The pin 157 providesa conductive path from cover 36 to contact terminal 94 (not shown inFIG. 24), which in this embodiment would be on an upper surface ofchassis 70. This embodiment provides the advantage that no apertures areneeded through a sealing portion 162 of gasket 38. Further, noconductive or insulating layers would need to be applied to the innersurface of the can 34.

FIGS. 25-28 show another embodiment of the present invention. Accordingto this embodiment, a different type of valve 170 is used in aninternally mounted fluid regulating system. The valve 170 includes avalve plate 172 having a plurality of apertures 174. These apertures,however, are not necessarily sized, shaped and positioned to correspondto fluid entry ports 32 in the bottom of can 34. This is because valveplate 172 is moved between a relative parallel relation with the bottomsurface 35 of can 34 (the valve closed position) and a bowed/flexedposition as shown in FIG. 25 (the valve open position). In thisconstruction, the apertures 174 in plate 172 do not line up or overlapwith any of fluid entry ports 32 so that no fluid may pass into the cellwhen plate 172 is parallel to the bottom 35 of can 34. To ensure plate172 is sufficiently pressed against the inner surface of can 34 to sealthe cell in a closed position, gasket 38 presses the peripheral edges ofplate 172 against can 34.

As shown in FIGS. 26 and 27, an alternative construction that utilizes avalve plate 172 secured at only one end under gasket 38 and having alatch 180 formed in can bottom 34. FIG. 26 shows the valve in an openposition while FIG. 27 shows the valve in a closed position. FIG. 28shows a perspective view of plate 172 with a SMA actuator 175 secured toplate 172 so as to cause plate 172 to lift and/or flex into the openposition. The movement of plate 172 in the open position may berestricted by the air electrode (not shown).

As described above, the fluid regulating system can use electroniccontrols to operate the valve, based in part on the cell (or battery)voltage. However, a switch can be used to close an electrical circuitthrough an actuator that changes length to move the valve to an open ora closed position, with the circuit subsequently being broken to stopthe flow of current through the actuator when the valve reaches the fullopen or closed position. This can eliminate the need for more complexcontrol circuits, while still drawing energy from the cell only whenneeded to open or close the valve. The switch can be on or within thebattery itself, or it can be a part of the device in which the batteryis used. In one embodiment, the device on/off switch also alternatelycloses the circuits through opposing actuators to open and close thevalve. The operation of such a fluid regulating system is illustrated inFIGS. 33A to 33D.

FIG. 33A includes a top view of a valve 260 similar to the valve 60shown in FIG. 3. Valve 260 includes a moveable plate 266 slidablydisposed in a chassis 270. Moveable plate 266 is shown in FIG. 33A inthe closed position (i.e., with apertures 268 out of alignment withapertures in a fixed plate). SMA actuators 282 a and 282 b are anchoredto the moveable plate 266 and opposite ends of the chassis 270 and areused to pull the plate 266 open and closed, respectively. Actuators 282a and 282 b are anchored to plate 266 via flat electrical contacts 277 aand 277 b, respectively, and to chassis 270 via electrical contacts 292a and 292 b, respectively. Flat contacts 277 a and 277 b are locatednear opposite ends of the top surface of plate 266 so they will makeelectrical contact with spring contacts 276 a and 276 b, respectively,when the plate 266 is in the open and closed positions, respectively.Spring contacts 276 a and 276 b also serve as contact terminals formaking connections to the remainder of a control circuit 290, which isrepresented schematically. The control circuit includes an on/off switch295 and the fluid depolarized battery 210 for providing electricalenergy to the device. When electrical energy is not required from thebattery 210, the switch 295 is in the off position and the valve 260 isin the closed position, as shown in FIG. 33A. Because neither of thecircuits including actuators 282 a and 282 b is closed, no current willflow through them, so the actuators 282 a and 282 b are at an ambienttemperature and in an elongated condition.

When the switch 295 is moved to the on position, current flows throughactuator 282 b, causing it to heat, shorten and pull plate 266 to theleft toward the open position. When plate 266 reaches the open position,as shown in FIG. 33B, the electrical connection between contacts 276 band 277 b is broken. When the circuit is broken, current ceases to flowthrough actuator 282 b. This accomplishes two things. First, noadditional energy is drawn from the battery 210 while the device remainsturned on, and second, actuator 282 b cools and returns to an elongatedcondition, as shown in FIG. 33C, so the plate 266 can be moved back tothe left when the device is turned off. When the switch 295 is moved tothe off position, the circuit that includes actuator 282 a is closed,and the flow of current therethrough causes it to shorten and pull theplate 266 to right, toward the closed position. When the plate 266reaches the closed position, the electrical connection between contacts276 a and 276 b is broken, as shown in FIG. 33D, and current ceases toflow through actuator 282 a, allowing the actuator to cool and elongate,as shown in FIG. 33A.

Electrical connections to contacts 276 a, 276 b, 277 a and 277 b can bemade in any suitable manner. For example connections can be made throughthe chassis 270 or through an interface between the top surface of thechassis 270 and the corresponding surface of an adjacent component, suchas a lid covering the chassis 270 and valve 260, to the edges of thefluid regulating system. In another example, electrical connections canbe made through suitably placed contacts extending through a lidcovering the valve 260. A switch that is part of the cell can be affixedto a suitable surface of the cell and/or fluid regulating system, suchas on an exterior surface of a lid. Alternatively, a switch can belocated on an outer surface of a multiple cell battery, or within adevice in which the battery is installed, with electrical connections tothe fluid regulating system made in a suitable manner, such as bywelding, soldering or pressure between corresponding contacts. In otherembodiments, more than two actuators can be used, in manner similar tothe embodiments shown in FIGS. 6, 7 and 8, for example.

Instead of incorporating the control circuit electronics within thefluid regulating system, they can be located externally. This may bedesirable in situations where they cannot be conveniently fitinternally, for example. In one embodiment the electronics can bemounted on an exterior side of the fluid regulating system, such aswithin a cap mounted on the side wall of the fluid regulating systemand/or the cell, as shown in FIG. 32. FIG. 32 shows a chassis 70,moveable plate 66, SMA wires 82 a and 82 b, and contact terminals 92′and 94 similar to those in FIG. 4. Unlike FIG. 4, however, the SMA wires82 a and 82 b in FIG. 32 are connected directly to the contact terminals92′ and 94, with no intermediate control circuit 90. The control circuitin FIG. 32 is contained in a circuit board 91 secured to the side of thechassis 70 with a cap 93 that protects the circuit board 91. The contactterminals 92′ and 94 on the chassis 70 make electrical contact withcorresponding terminals on the surface of the circuit board 91.Electrical contact can be made in any suitable manner, such as bypressure contact. The circuit board 91 can have a single substratelayer, or it can be a laminated substrate with two or more layers. Theelectronics components and electrical connections can include printed ornon-printed components, or combinations thereof. Larger components canbe disposed in recesses in the surfaces of the circuit board 91 toprovide flush fits with the chassis 70 and cap 93. The electricalconnections between the circuit board 91 and the cell are not shown, butthese connections could also be made through the chassis 70.

The fluid regulating system 50 is further illustrated in FIGS. 36-43employing an actuator having SMA wires 82 a and 82 b and a lever 84 foractuating the moving plate 66, according to various additionalembodiments. The lever 84 illustrated in FIGS. 36 and 37 is shownpivotally connected at pivot pin 86, near one end of lever 84, tochassis 70 such that lever 84 rotates about pivot pin 86 in response toSMA wires 82 a and 82 b to leverage movement of plate 66. Actuator pin88 near the opposite end of lever 84 engages plate 66.

Connected on the top surface of lever 84 is an electrical conductor 310having a sliding spring contact 312 provided at one end. SMA wires 82 aand 82 b are connected to the electrical conductor 310 at attachmentpoint 89. The sliding spring contact 312 is in electrical contact withan electrical circuit trace 314 provided on the top surface of chassis70. The sliding spring contact 312 is spring biased downward to forciblycontact the top surface of circuit trace 314 to maintain adequateelectrical connection therewith as lever 84 is rotated about pivot pin86. In one embodiment, the circuit trace 314 may be connected toelectrical ground, such that the electrical current applied to one ofSMA wires 82 a and 82 b is conducted onto the conductor 310 to circuittrace 314 and to ground.

In FIG. 38 the lever 84 is shown employing an electrical wire 316connected between conductor 310 and circuit trace 314, in lieu of thesliding spring contact. One end of the wire 316 is connected toconductor 310 at pivot pin 86 and the other end is connected to circuittrace 314 at connector 318 to complete the circuit path to ground. Whilecircuit trace 314 is described herein connected to electrical ground, itshould be appreciated that electrical current could be supplied tocircuit trace 314 and a grounded path connection may be provided via oneof the SMA wires 82 a and 82 b, to conduct electrical current in thereverse direction.

Referring to FIGS. 39-41, a fluid regulating system 50 is shownemploying a rotating lever 84, according to another embodiment of thepresent invention. In this embodiment, lever 84 employs a first centralelongated pivot pin 86′ that extends downward through an elongated slot320 in moving plate 66 and into engagement with opening 322 instationary plate 62. Opening 322 allows rotation of central pivot pin86′ and prevents lateral movement of the pin 86′. Lever 84 has a secondpin 88 displaced by a distance from the central pivot pin 86′ thatengages opening 67 in moving plate 66. The SMA wires 82 a and 82 b areshown connected to lever 84 at locations displaced from the centralpivot pin 86′. When actuated, the SMA wires 82 a and 82 b apply torqueto rotate lever 84 either clockwise or counterclockwise about centralpivot pin 86′.

As seen in FIG. 40, with SMA wire 82 a electrically energized, SMA wire82 a heats up and contracts to pull lever 84 to rotate in acounterclockwise direction such that lever 84 rotates about centralpivot pin 86′ and causes moving plate 66 to slide to the left as shown.As seen in FIG. 41, electrically energizing the SMA wire 82 b heats SMAwire 82 b which contracts and pulls lever 84 to rotate in a clockwisedirection about center pivot pin 86′ such that the moving plate 66slides to the right. It should be appreciated that as the lever 84 isrotated clockwise or counter-clockwise, the moving plate 66 slides rightor left by way of actuator pin 88, and the central pivot pin 86′ doesnot interfere with movement of plate 66 due to the presence of theelongated slot 320.

A fluid regulating system 50 is further illustrated in FIGS. 42-44employing a lever 84 that is formed integrally as a part of the chassis70 having a flexible hinge 86″. In this embodiment, the lever 84 may beformed of the same material (e.g., epoxy) integrally formed as part ofchassis 70, prior to forming the overmold body 300 or may be formed aspart of the overmold body 300. The lever 84 is formed having actuatorpin 88 extending downward into engagement with opening 67 in movingplate 66. SMA wires 82 a and 82 b are connected to the lever 84. Lever84 has a reduced width portion 86″ that serves as a flexible hinge suchthat the lever 84 bends about the flexible hinge 86″ responsive to SMAwires 82 a and 82 b so as to move actuator pin 88 and plate 66 to theleft, as shown in FIG. 43, and to the right, as shown in FIG. 44, toopen and close the valve. It should be appreciated that the flexiblehinge 86″ is sufficiently thin and made of material that allows forsufficient movement of lever 84 when SMA wires 82 a and 82 b areenergized.

Referring to FIG. 45, a fluid regulating system 50 is illustrated forregulating fluid (e.g., air) to a battery by controlling the opening andclosing of the valve and further includes a passive temperature closureaccording to a further embodiment of the present invention. SMA wire 82a may be electrically energized to heat up and contract and thereby movemoving plate 66 to the open valve position (as shown in FIG. 45) viaactuator pin 304 a. SMA wire 82 b may be electrically energized to heatup and contract and thereby move moving plate 66 to the closed valveposition via actuator pin 304 b. The valve may therefore be activelyopened and closed in response to electric current applied to either SMAwires 82 a or 82 b. Additionally, the SMA wires 82 a and 82 b areselected with different actuation temperatures to provide a passivetemperature closure of the valve, according to one embodiment of thepresent embodiment. The SMA wires 82 a and 82 b have an unbalancedactuation temperature to achieve the desired passive closure of thevalve. Thus, the moving plate 66 is moved to the closed valve positionupon experiencing a predetermined temperature limit.

In the embodiment shown and described in FIG. 45, the SMA wire 82 a isconfigured with a first actuation temperature of about 90° C., whereasthe SMA wire 82 b is configured with a lower second temperature of about60° C. When electrically energized, SMA wire 82 a heats up and contractsto apply force to actuate moving plate 66 to the open position uponreaching the higher first temperature. Similarly, SMA wire 82 b may beelectrically energized to heat up and contract to actuate the valve tomove moving plate 66 to the closed position at the lower secondtemperature. The first temperature is greater than the secondtemperature such that the SMA wire 82 b closes the valve when thetemperature of SMA wire 82 b reaches the lower second temperature. Itshould therefore be appreciated and in addition to actively opening andclosing the valve based on electrical current applied to the SMA wires82 a and 82 b, the SMA wire 82 b forces the moving plate 66 to theclosed valve position when the ambient temperature first reaches thelower second temperature. If the temperature of the environmentcontinues to rise to the higher second temperature, the SMA wire 82 awill not apply sufficient force to change the position of the valve fromits closed position.

SMA wires 82 a and 82 b may include commercially available SMAcomponents. One example of a 60° C. actuation SMA wire is a 0.102 mm(0.004 inch) diameter 60° C. wire, commercially available from Flexinol.One example of a 90° C. actuation SMA wire is a 0.076 mm (0.003 inch)diameter 90° C. wire, commercially available from Flexinol. In theexample given, the 60° C. SMA wire will remain contracted until thetemperature has dropped back down to about 40° C., thereby resulting ina temperature hysteresis.

The fluid regulating system 50 employing the unbalanced temperature SMAwires advantageously provides a passive method for closing the valve toprevent fluid ingress to the battery cell above a predeterminedtemperature. By closing the fluid regulating system 50 at apredetermined temperature, such as 60° C., degradation of the batterymay be minimized or prevented. Additionally, by moving the valve closedupon reaching a temperature limit, such as 60° C., opening of the valveat high temperatures is prevented. It should be appreciated that thepredetermined temperature for closing the valve may be greater than 45°C., and more particularly, may be set at about 60° C.

According to one embodiment, the SMA wires 82 a and 82 b may beconfigured having different sizes to generate different actuation forcessuch that the SMA wire 82 b generates a greater actuation force than theactuation force generated by SMA wire 82 a. In an exemplary embodiment,SMA wire 82 b has a greater cross-sectional area, such as a greaterdiameter, than SMA wire 82 a. With a larger cross-sectional area, SMAwire 82 b applies a greater closing force to the moving plate of thevalve in the event that the ambient temperature reaches the higher firsttemperature. It should be appreciated that the SMA wires 82 a and 82 bmay be circular in cross-section and the second SMA wire has the largerdiameter. According to other embodiments, the SMA wires 82 a and 82 bmay have other cross-sectional shapes, such as oval, square orrectangular shapes, with the second SMA wire 82 b having a greaterdimension, resulting in a greater cross-sectional area, which results ina greater actuation force than the first SMA wire 82 a. In anotherembodiment, SMA wires 82 a and 82 b may have both differentcross-sectional areas and different phase transition temperatures, suchthat SMA wire 82 b will generally be actuated first as the ambienttemperature increases, which results in the valve remaining closed evenas the ambient temperature rises above the higher phase transitiontemperature of SMA wire 82 a.

Referring to FIGS. 46-50, a fluid consuming battery 10 is shown having abattery cell 20 and a fluid regulating system 50 having a fluid passagethrough the chassis body 300 that provides for pressure equalizationbetween the cell 20 and the outside environment, according to twoembodiments. In the embodiments shown, a chassis is generallyillustrated by the overmold body 300 having a central opening 332 and aninward extending ledge 354. A fluid consuming battery cell 20, such asan air cell, is connected on the top surface of the chassis 300. Thefixed plate 62 with fluid entry ports 64 is connected to the bottomsurface of chassis 300 and moving plate 66 with ports 68 is disposedbetween the lower wall of inward extending ledge 354 and fixed plate 62so that plate 66 may be moved relative to plate 62.

In the embodiment shown in FIGS. 46-49, the overmold chassis body 300 isgenerally illustrated having a first port, also referred to as an inlet350, located generally between the cell 20 and the moving plate 66, andin fluid communication with opening 332 and cell 20. The chassis body300 also has a second port, also referred to as an outlet 352, providedon the outside of the overmolded material leading to the outsideenvironment. The overmolded chassis 300 is manufactured to have anonporous outside layer 360 and a porous internal volume that providesthe fluid passage 356. The nonporous outside layer 360 is generallynon-permeable to fluid, particularly air, and may include an epoxy,according to one example. The porous internal volume provides for apressure equalization fluid flow passage 356 that extends from the inlet350 to the outlet 352. The porous internal volume may include an airpermeable material, such as microporous polytetrafluoroethylenematerial, or a non-woven porous material that allows restricted air flowat a low diffusion rate through the passage 356. Alternatively, or inaddition, the fluid passage 356 may include empty void volume providinga sufficiently restricted passage that allows air flow at a lowdiffusion rate. The fluid passage 356 advantageously allows air toslowly pass from the inlet 350 to outlet 352, however, the fluid passage356 may allow fluid to pass in either direction between the inlet 350and outlet 352 to provide pressure equalization between the cell 20 andthe outside ambient environment.

The inlet 350 of fluid passage 356 is in fluid communication with theopen volume between the battery cell 20 and valve plates 66 and 62. Apressure differential existing between gases within the battery cell 20and outside environment may allow gas to migrate through the fluidpassage. When the battery cell 20 generates gas, the gas may migratethrough the restricted fluid passage 356 to the outside environment toprevent compromising the seal between the valve plates 66 and 62.Contrarily, gas may be permitted to flow from the outlet 352 to theinlet 350, but is generally restricted such that air is not freelysupplied to the battery cell 20 so that the cell 20 is generally notdischarged at a high rate when the valve is closed.

According to one embodiment, the fluid passage 356 has an air diffusionrate that would result in a loss of no more than 10 percent of the cellcapacity per year at room temperature due to moisture gain or loss. Itshould be appreciated that the porous volume of the fluid passage 356may include a membrane that is generally porous to gases to provide atortuous or restricted air flow passage, but does not allow freeunrestricted flow of fluid into the cell 20. According to oneembodiment, the porous volume 356 may include a tortuous fluid passage356, such as that provided by baffles 358 as shown in FIG. 49. Thebaffles 358 essentially increase the effective length of the airflowpassage 356 through the overmolded chassis 300, thus increasing the neteffective fluid flow path length. According to other embodiments, thetortuous fluid flow path may employ a honeycomb pattern that isgenerally porous to allow excess gas to escape from the cell 20 to theoutside environment, while minimizing the amount of air from enteringthe cell 20.

In the embodiment shown in FIG. 50, the top surface of the overmoldchassis body 300 has a slot 334 formed therein in a generally serpentineshape that extends from the inside opening 332 in a rectangular shapeabout the opening 332 by about 360° leading to the outside surface ofthe chassis 300. Disposed within the slot 334 is a hollow tube 336having a general configuration adapted to be sized and fit within slot334. The tube 336 has a first port, also referred to as an inlet 338, atone end in fluid communication with the inside opening 332 of thechassis 300 and cell 20, and has a second port, also referred to as anoutlet 340, at the other end in fluid communication with the outsideenvironment. The fixed plate 62 is shown connected on the bottom surfaceof chassis 300. The moving plate 66 is disposed below ledge 354 and isadjacent to and in sealed relationship with the fixed plate 62, suchthat plate 66 is moveable relative to plate 62 to open and close thevalve.

The tube 336 provided within chassis 300 provides a fluid passage thatextends between the inlet 338 and outlet 340 such that fluid releasedfrom the battery cell 20 is able to pass through the fluid passage oftube 336 to the outside environment. The fluid inlet 338 is located inposition in the volume of opening 332 between the battery cell 20 andthe fixed and moving plates 62 and 66, according to one embodiment.Thus, the extended length and small diameter of tube 336 provides atortuous fluid passage that allows fluid to escape from the cell 20 at asufficiently low diffusion rate, while sufficiently restricting airingress to the cell 20 due to the low diffusion rate. In one embodiment,tube 336 has a sufficiently restricted inner diameter of less than 0.5mm and an effective length of at least 200 mm. According to anotherembodiment, the slot 334 may be covered and utilized as the fluidpassage in lieu of use of the tube 336.

In the disclosed embodiments of FIGS. 46-50, a pressure differentialexisting between the gases within the battery cell 20 and the ambientoutside environment in which the cell 20 is exposed may cause adisruption, which may lead to subsequent failure of the fluid barrier.Thus, the intended primary seal barrier between the valve plates 62 and66 can be compromised, which would potentially allow uncontrolledingress and egress of fluid, such as water, oxygen, hydrogen, and carbondioxide, which could result in the unacceptable loss of batteryshelf-life. The pressure equalization fluid passage 336 or 356 providedin chassis 300 allows fluid such as gases to migrate through the fluidpassage to egress and ingress. By providing an appropriately sized holeof a suitable length, the fluid passage allows for the egress of gas,such as hydrogen generated within a metal-air cell, while prohibitingexcess ingress of oxygen and carbon dioxide to the cell 20.

Referring to FIGS. 51-54, a fluid regulating system 50 is generallyillustrated employing a moving plate 366 that rotates relative to astationary plate 362, according to two embodiments. In the embodimentshown in FIGS. 49 and 50, the fluid regulating system 50 employs arotatable plate 366 assembled to a chassis 370 and aligned on top of astationary plate 362. The stationary plate 362 has a pair of openings364 and moving plate 366 has a pair of openings 368 that align in fluidcommunication with each other to control fluid entry to a battery cell(not shown). Stationary plate 362 remains fixed to chassis 370. Therotatable plate 366 rotates about a pivot pin 371, between a closedvalve position shown in FIG. 51 and an open valve position shown in FIG.52. In the closed valve position, the openings 364 and 368 are notaligned so as to prevent fluid from flowing into a battery cell. In theopen valve position, the openings 364 and 368 are aligned to allow fluid(e.g., air) to enter the battery cell.

The fluid regulating system 50 illustrated in the embodiment of FIGS. 51and 52 employs SMA wires 82 a and 82 b connected to the chassis 370 atcrimps 372 and 374. The SMA wires 82 a and 82 b are further attached torotatable plate 366 at a crimp 375. The SMA wires 82 a and 82 b extendwithin a channel or slot 380 between the pair of crimps 372, 374 andcrimp 375, and the SMA wires 82 a and 82 b are connected to therotatable plate 366 at a distance from pivot pin 371 so as to causeplate 366 to rotate between the open and closed valve positions. Ineffect, the rotatable plate 366 with connection to the SMA wires 82 aand 82 b has an integrally formed lever that leverages force applied bySMA wires 82 a and 82 b at a distance from the pivot pin 371 to rotaterotatable plate 366. Additionally, springs 377 and 379 are provided ontop of the rotatable plate 366 to provide a retaining force to retainrotatable plate 366 in a sealed relationship with the stationary plate362 in the vicinity of the holes 364 and 368. Is should be appreciatedthat more or less fluid entry holes may be provided in the rotatable andstationary plates 366 and 362 as should be evident to those skilled inthe art.

Referring to FIGS. 53 and 54, a fluid regulating system 50 is generallyillustrated having a rotatable plate valve assembly, according to afurther embodiment. In this embodiment, a lever 484 is shown connectedto a rotatable plate 466 having generally tapered slot openings 468.Below the rotatable plate 466 is a stationary plate 462 which likewiseincludes similarly shaped tapered slot openings 464 that may align withthe openings 468 in the open valve position to allow fluid entry into abattery cell (not shown). With plate 462 fixed, rotatable plate 466rotates clockwise and counterclockwise to close and open the valve

The lever 484 is shown having a pivoting hip 486 generally disposedwithin a frame plate, such as the chassis 470. The lever hip 486 isgenerally round in shape and is engaged within the frame plate 470 byway of resilient arms 490. Arms 490 can help to hold the round hip 486in place to provide a low degree of variability in the location ofactuator pin 488, thereby providing low variability in alignment ofopenings 464 and 468. The hip 486 allows lever 484 to rotate from acounterclockwise position with one shoulder 492 in contact with plate470 as seen in FIG. 53 into a position with the other shoulder 494 incontact with plate 470 as seen in FIG. 54 in response to actuationprovided by SMA wires 82 a and 82 b. Shoulder 492 and 494 serve as endof travel stops and may be omitted in other embodiments. The SMA wires82 a and 82 b are shown connected to the frame plate 470 by way of apair of crimps 496 and 498, and are further connected together withinlever 484 via another crimp 499. It should be appreciated that the crimp499 may include an electrical ground path or the ground path may beprovided through an alternative conductive path.

In operation, the fluid regulating system 50 of the present embodimentis actuated by electrically energizing one of the SMA wires 82 a or 82 bto rotate lever 484 to move plate 466 between open and closed valvepositions. It should be appreciated that the tapered slots 464 and 468provide gearing of the actuation from SMA wires 82 a and 82 b followingthe increase in stroke as the radius from the hip 486 increases.

The rotational valves illustrated in FIGS. 51-54 provide for rotation ofthe moveable plate relative to the stationary plate. It should beappreciated that, alternately, linear actuation of the plate may beachieved or a combination of linear movement and rotation movement ofthe moving plate relative to the stationary plate may be achieved,according to other embodiments. Further, while the valve has beendescribed in connection with a moving plate and a stationary plate, itshould be appreciated that the valve may include one or two movingplates, such that one plate moves relative to the other plate to openand close the valve.

Although the present invention has been described above with respect tosingle batteries having a single cell, aspects of the present inventionmay apply to batteries having multiple cells, and battery packs havingmultiple batteries. For example, the fluid regulating system may becompletely or partially disposed in a housing of a battery pack so as toselectively open and close a valve that allows air or another fluid topass into the battery pack housing. In this case, separate fluidregulating systems would not be needed for each battery. Further, thefluid regulating system could be powered from any one or group of thebatteries or all of the batteries within the battery pack or fromanother battery outside the battery pack.

The fluid regulating system may also be disposed completely or partiallywithin a device that is powered by the battery, batteries, or batterypack or otherwise provided separate from the battery, batteries, orbattery pack. For example, the valve could be a pre-packaged module thatserves a variety of multi-cell pack sizes. So there may be advantages topackaging the valve, valve power supply and controls separately from thefluid consuming cells.

The combination of a fluid consuming battery and a fluid regulatingsystem can include a module containing all or a portion of the fluidregulating system into which one or more replaceable fluid consumingbatteries are inserted. This allows reuse of at least part of the fluidregulating system, thereby reducing the cost per battery to the user.The module can include one or more fluid inlets and can also includeinternal channels, plenums or other internal spaces that provide apassageway for fluid to reach the battery. The module and battery can beheld together in any suitable manner, including the use of electricalcontacts that are part of the module that cooperate with thecorresponding electrical contacts that are part of the battery toprevent inadvertent separation of the module and battery. For example,the electrical contacts on the module can be in the form of projectingblades that snap into slots in the battery case that contain the batteryelectrical contacts. The blades can be held in the slots by any suitablemeans, such as by interference fit, one or more springs, a mechanicallocking mechanism and various combinations thereof. The module andbattery dimensions, shapes and electrical contacts can be configured toallow mating of the module and battery in only the proper orientationsin order to assure proper electrical contact and prevent batteryreversal. The module, the battery or both can have external contactterminals for making proper electrical contact with a device in whichthe combined battery and module are installed. In some embodiments thebattery can be replaced without removing the module from the device.

While the invention has been described in detail herein in accordancewith certain preferred embodiments thereof, many modifications andchanges therein may be affected by those skilled in the art withoutdeparting from the spirit of the invention. Accordingly, it is ourintent to be limited only by the scope of the appending claims and notby way of the details and instrumentalities describing the embodimentsshown herein.

1. A battery comprising: a cell comprising: a cell housing having atleast one fluid entry port for the passage of a fluid into said cellhousing; a first fluid consuming electrode; and a second electrode,wherein said cell housing comprises a can and a cover sealed together toform an interior in which said electrodes are disposed and wherein outersurfaces of said can and said cover define outer surfaces of said cellhousing; and a fluid regulating system disposed so as to selectivelyallow fluid to enter into said at least one fluid entry port so as toreach said first fluid consuming electrode, wherein said fluidregulating system comprises: a moving plate disposed adjacent anexterior surface of said cell housing and having at least one plateaperture for moving in and out of alignment with said at least one fluidentry port, a chassis including an aperture for slidably receiving saidmoving plate and an actuator comprising a shape memory alloy componentfor moving said moving plate when heat is applied to said shape memoryalloy component.
 2. The battery of claim 1, wherein said moving plateslides linearly relative to said cell housing.
 3. The battery of claim 1and further comprising a lid covering said moving plate and providing apassage for fluid to said moving plate.
 4. The battery of claim 3,wherein said lid further covers said actuator.
 5. The battery of claim1, wherein heat is applied to said shape memory alloy component when acurrent is passed through said shape memory alloy component.
 6. Thebattery of claim 1, wherein said moving plate is substantially flat. 7.The battery of claim 1, wherein said fluid regulating system is at leastpartially provided in a module, wherein said module is removable fromsaid cell housing such that the cell may be replaceable with anothercell.
 8. The battery of claim 7, wherein said module comprises a fluidinlet and a passageway between said module and said cell housing forfluid to reach said cell when said cell and said module are assembledtogether.
 9. The battery of claim 7, wherein, after assembly together,said module and said cell cooperate to prevent inadvertent separation ofsaid module and cell.
 10. The battery of claim 7, wherein said modulecomprises electrical contact terminals through which electrical energycan be provided from said cell to an electrical device.
 11. The batteryof claim 1, wherein said fluid entry port is formed through of said canand said moving plate is disposed adjacent an exterior surface of saidcan.
 12. A battery comprising: a cell comprising: a cell housing havingat least one fluid entry port for the passage of a fluid into said cellhousing; a first fluid consuming electrode; and a second electrode,wherein said cell housing comprises a can and a cover sealed together toform an interior in which said electrodes are disposed and wherein outersurfaces of said can and said cover define outer surfaces of said cellhousing; and a fluid regulating system disposed so as to selectivelyallow fluid to enter into said at least one fluid entry port so as toreach said first fluid consuming electrode, wherein said fluidregulating system comprises: a moving plate disposed adjacent anexterior surface of said cell housing and having at least one plateaperture for moving in and out of alignment with said at least one fluidentry port, a chassis including an aperture for slidably receiving saidmoving plate and an actuator for moving said moving plate, and a lidcovering said moving plate and providing a passage for fluid to saidmoving plate.
 13. The battery of claim 12, wherein said lid furthercovers said actuator.
 14. The battery of claim 12, wherein said actuatoris disposed on said chassis.
 15. The battery of claim 12, wherein saidchassis includes at least one hole, and wherein said lid includes atleast one stand-off extending through said hole for attachment to saidcell housing.
 16. The battery of claim 12, wherein said chassis includesat least one hole that is filled with a material that attaches to saidlid and to said cell housing.
 17. The battery of claim 12, wherein saidchassis comprises a printed circuit board.
 18. The battery of claim 12,wherein said lid is made of plastic.
 19. The battery of claim 12,wherein said lid is made of an electrically conductive material.
 20. Thebattery of claim 19, wherein said lid is electrically coupled to saidcell housing.
 21. The battery of claim 12, wherein said fluid entry portis formed through a side of said can and said moving plate is disposedadjacent an exterior surface of said can.